Hydrocarbon gels



StatesPatent O HYDROCARBON GELS No Drawing. Application March 16, 1955Serial No. 494,801

9 Claims. (Cl. 44-7) This application is a continuation-in-part of mycopending application Serial No. 449,523, filed August 12, 1954 (nowPatent No. 2,798,100), which is a continuation-inpart of my applicationSerial No. 360,838, filed June 10, 1953 (now Patent No. 2,798,098),which is a continuation-in-part of my application Serial No. 212,839,filed February 26, 1951, and now abandoned. This application relatesgenerally to new compositions of matter comprising gelled hydrocarbons,and more specifically, to new compositions comprising hydrocarbons and adiaryl-desoxy-ketitol. Still more specifically, this invention relatesto a new composition of matter comprising a hydrocarbon and a productformed by condensing a ketose with two molecular proportions of anaromatic hydrocarbon in the presence of a condensation catalyst atcondensation conditions. The new compositions of matter of the presentinvention are useful for military purposes, particularly where semisolidor gelled fuels are desirable. Semisolid or gelled fuels are utilized bythe military forces in bombs of the bursting and tail-ejection type, andas incendiaryfuels for use in flame throwers, hand grenades, etc.

Prior to World War II, semisolid or gelled fuels were produced by addingrubber, particularly natural rubber, to gasoline and similar hydrocarbonliquids. The shortage of rubber during World War II to a widespreadsearch for substitute gelling agents for hydrocarbons. Substitutegelling agents utilizedwidely during World War II (and since then)include soaps of polyvalent metals, particularly aluminum. Thesealuminum soaps which have been used for this purpose are two main types.One type comprises a group of aluminum salts of saturated fatty acidssuch as the aluminum laurates, palmitates, stearates, and myristrates.The second type of aluminum soaps utilized were the aluminum oleates.Certain mixtures of these two types of aluminum soaps were and are inWidespread use for the production of munitions. The most satisfactorycompositions are described in U.S. Patent 2,606,107. However, thesegelled hydrocarbon compositions still suffer from an inherentdeficiency, namely, they contain metals, particularly aluminum. As iswell known, the presence of even minute traces of certain metals inhydro-' carbons catalyze deleterious reactions such as oxidativedeterioration, polymerization, etc. Therefore, gelled hydrocarboncompositions utilized prior to the present invention could not andcannot bekept stored for any lengthy period of time. For militarypurposes itis common and diaryl-desoxy-ketitol.

formed by reacting a ketose sugar or a ketose carbo-j hydrate with twomolecular proportions of an aromatic compound to yield products in whicheach of the-a'ryl has-been found necessary to prepare these gelledhydrobon atom' of the ketose.

carbons as near in time as to actual use as is possible. These and otherdeficiencies can be readily overcome by the utilization of thecompositions of the present invention. Since the compositions of thepresent invention are totally organic, the difiiculties enumeratedhereinabove are not encountered.

In one embodiment, the present invention relates to a composition ofmatter comprising a hydrocarbon and a diaryl-desoxy-ketitol. I

In another embodiment the present invention relates to a composition ofmatter comprising an aromatic hydrocarbon and a diaryl-desoxy-ketitol.

Still another embodiment of this invention relates to a new compositionof matter comprising a hydrocarbon and a ditolyl-desoxy-ketitol.

A further embodiment of this invention relates to a composition ofmatter comprising an aromatic hydrocarbon and a ditolyl-desoxy-ketitol.

As set forth hereinabove, the novel compositions of matter of thepresent invention comprise gelled mixtures of hydrocarbons and theproduct formed by condensing a ketose with two molecular proportions ofan aromatic hydrocarbon in the presence of a condensation catalyst atcondensation conditions. The hydrocarbon with which thediaryl-desoxy-ketitol is composited may be selected from innumerablepure hydrocarbons and mixtures thereof. The hydrocarbon or hydrocarbonsmay be saturated, unsaturated, or aromatic. The aromatic hydrocarbonsare particularly preferred. Hydrocarbons utilizable in forming the newcomposition of matter of the present invention include normal butane,isobutane, pentanes, hexanes, heptanes, octanes, nonanes, decanes,undecenes, etc., including their many isomeric structures; butenes,including l-butene, Z-butene, and isobutylene, pentenes, hexenes,heptenes, octenes, noncnes, decenes, undecenes, dodecenes, etc.,including their many isomeric structures; cyclopentane,methylcyclopentane, dimethylcyclopentane; cyclohexane,methylcyclohexane, ethylcyclohexane, di-

methylcyclohexane, etc; cyclopentene, methylcyclopentene,ethylcyclopentene, dimethylcyclopentene, diethylcyclopentene,cyclohexene, methylcyclohexene, ethylcyclohexene, dimethylcyclohexene,etc.; and benzene, toluene, o-xylene', m-xylene, p-xylene, ethylbenzene,cumene, cymenes, etc. Hydrocarbon fractions such as those derived frompetroleum or vegetable sources, are also within the scope of thisinvention and include such fractions as gasoline (leaded or unleaded),naphtha, petroleum ether, Stoddards solvent, diesel oil, light cycleoil, fuel oil, turpentine, dipentene, etc. A particularly preferredbydrocarbon fraction is catalytically reformed gasoline containing morethan 10% aromatic hydrocarbons. Examples of other hydrocarbonsutilizable within the broad scope of this invention are readily apparentto one skilled in the art.

The novel composition of the present invention comprises a hydrocarbon,as described hereinabove, and a These diaryl-desoxy-ketitols are groupsis bound chemically to the original carbonyl car The condensation of'ardl matic hydrocarbon with a ketose sugar or ketose carbohydrate maybe carried out in the presence of various condensation catalysts atcondensation conditions. For example, this condensation reaction may becarried out in the presence of hydrogen fluoride at a temperature ofabout -20 to about 100 C. and preferably at a temperature of from aboutto about 50 C. Other suitable catalysts include metal halides of theFriedel- Crafts type, particularly aluminum chloride, as such ormodified by the addition thereto of an alcohol, ether, ester,nitroparafiin, alkyl halide, and the like. Mixtures of boron trifluorideand hydrogen fluoride may also be employed. These condensation reactionsmay be carried out in glass or steel equipment depending upon theparticular condensation catalyst utilized, or in other suitableapparatus constructed from silver, copper, and certain alloys such asMonel metal and the like. The pressure at which the reaction is carriedout will vary from atmospheric pressure to pressures of 50 or 100atmospheres .or more and will be dependent upon the particularcondensation catalyst utilized, the reaction temperature employed, themol fractions of reactants utilized, and the volume of the particularreactor in which the condensation reaction is conducted. In manyinstances, it is convenient to operate at the pressure generated by themixture of reactants and catalyst employed.

Aromatic hydrocarbons suitable for use in the production of thediaryl-desoxy-ketitols utilized in the composition of the presentinvention include benzene, toluene, o-Xylene, m-xylene, p-xylene,ethylbenzene, 1,2,3- trimethylbenzene, 1,2,4-trimethylbenzene,1,3,5-trimethyl benzene or mesitylene, o-ethyl toluene, p-ethyl toluene,n-propylbenzene, isopropylbenzene or cumene, butylbenzene, amylbenzene,and higher molecular weight alkylaromatic hydrocarbons such as formed bythe alkylation of low molecular weight aromatic hydrocarbons withalkylating agents such as olefin polymers, i.e., nonenes, dodecenes,etc. formed from the polymerization of propylene. These higher molecularweight alkylaromatic hydrocarbons include such materials ashexylbenzenes, hexyltoluenes, dodecylbenzenes, dodecyltoluenes, etc.Often, alkylate is obtained as a high boiling fraction in which case thealkyl group attached to the aromatic hydrocarbon may contain from about6 to about 24 carbon atoms.

Other aromatic hydrocarbons suitable for conversionintodiaryl-desoxy-ketitols include those with two or more aryl groups, suchas diphenyl, diphenylmethane, triphenylmethane, etc. Also, examples ofsuitable aromatic hydrocarbons which contain condensed benzene ringsinclude naphthalene, anthracene, phenanthrene, and also alkylatednaphthalenes, alkylated anthracenes, and the like.

The ketoses which are condensed with aromatic hydrocarbons to form thediaryl-desoxy-ketitols utilized in the novel compositions of matter ofthis invention, are monosaccharides, and according to their chemicalnature may be considered to be hydroxy ketones. According to the numberof oxygen atoms present in the molecule of the ketones, they are calledtrioses, tetroses, pentoses, hexoses, and the like. These ketoses havethe general formula C,,H ,,0,, in which n generally equals 3 to about 8.With the exception of the simplest ketose, dihydroxyacetone, all ofthese monosaccharides have one or more asymmetric carbon atoms and musttherefore occur in stereoisomeric forms.

The diarylated ketoses or diaryl-desoxy-ketitols may also be preparedfrom aromatic hydrocarbons and polysaccharides which yield ketose unitson hydrolysis. Such polysaccharides includes sucrose, inulin, turanose,raffinose, gentianose, melezitose, stachyose, and verbascose.

The simplest ketoses which may be condensed with aromatic hydrocarbonsto form the diaryl-desoxy-ketitols 4 utilized in the novel compositionof this invention may be represented by the formula:

CHzOH i (CHOH) in which n is an integer from about 1 to about 8 and Brepresents hydrogen and CH OH. As an example of the utility of thisgeneral formula, when n equals 1 and B equals hydrogen, the compound isthen symmetrical dihydroxyacetone; when n equals 1 and B equals CH OH,the compound is erythrose; when n equals 2 and B equals CH OH, thecompound is riboketose or xyloketose; when n equals 3 and B equals CHOH, the compound is psicose, fructose, sorbose, or tagatose; and when nequals 4 and B equals CH OH, the compounds are heptoses.

As set forth hereinabove, the novel compositions of matter of thepresent invention comprise a hydrocarbon and a diaryl-desoxy-ketitolprepared by condensing a ketose with two molecular proportions of anaromatic hydrocarbon at condensation conditions in the presence of acondensing agent. Suitable condensing agents set forth include aluminumchloride, as such or modified, other Friedel-Crafts metal halides,mixtures of hydrogen fluoride and boron 'trifluoride, and hydrogenfluoride itself. When hydrogen fluoride itself is utilized as thecondensing agent, it may be used in anhydrous form or diluted with waterto make a hydrofluoric acid of the desired concentration. Thehydrofluoric acid may also be modified or diluted further with variousinert diluents' when it is desired to operate the process with lowhydrogen finoride concentrations. Suitable inert diluents includeperfluoro derivatives of normal paraffinic hydrocarbons such asperfluoropropane, perfluoro-n-butane, perfluoro-n-pentane, etc. In someinstances, hydrofluoric acid of from about to about HF concentration isdesirable, and in some other instances, it is more desirable to usesubstantially anhydrous hydrogen fluoride as the catalyst.

When hydrogen fluoride is utilized as the condensation agent, thecondensation reaction may be carried out by adding hydrogen fluorideslowly to a stirred mixture of the aromatic hydrocarbon and ketose, or,reversely, the mixture of aromatic hydrocarbon and ketose may be addedwith stirring to hydrogen fluoride while maintaining the condensationtemperature at from about 20 to about 100 C. By using suitable coolingand/ or heating means, it is often advisable or desirable to comminglethe reactants and condensing agent at a relatively low temperature suchas from about -80 to about 30 C. and then to permit the reaction mixtureto warm gradually While the reactants and catalyst are stirred bysuitable means such as a motor driven stirrer or other mixing equipment.After the reaction has reached the desired degree of completion, thehydrogen fluoride condensing agent may be removed from the reactionmix-' ture by distillation at atmospheric pressure or lower or bypassing an inert gas through the reaction mixturewhile maintaining it atrelatively low temperature. Also, the entire reaction mixture andcatalyst may be mixed with water or may be added to ice in order toquench the activity of the condensing agent and to permit sepa ration ofthe organic reaction products and unreacted starting materials from thecatalyst. The organic reaction products may also be separated from thecondens-' ing agent by means of an organic solvent such as ether inwhich some of the organic material may be dissolved.

Further methods of isolating the reaction products areillustrated in theexamples.

The novel compositions of matter of this invention may be preparedsimply by admixing the desired hydro:

carbon or hydrocarbon mixture or hydrocarbon raction with the desireddiaryl-desoxy-ketitol. In general, to"

3 form stable gels, the amount admixed with the desired hydrocarbon"will range from about 0.1 to about 25% by weight. Of course, themaximum amount by weight of the diaryl-desoxy-ketitol which is admixedwith the hydrocarbon will depend upon the specific solubility of theparticular diaryl-desoxy-ketitol therein. Thus, where thediaryl-desoxy-ketitol is produced from an aromatic hydrocarboncontaining long chain alkyl groups, the diaryl-desoxy-ketitol will bemore compatible with the hydrocarbon than when lower molecular weightaromatic hydrocarbons are used in forming or producing thediaryl-desoxy-ketitol. Since the diaryldesoxy-ketitol is the moreexpensive of the two components of the novel composition of thisinvention, a minimum quantity to form the desired gel will be in mostcases the maximum quantity utilized. This minimum amount of course canvary as it may be desirable to vary the stiffness of the gel from timeto time. In most cases, the preferred amount of diaryl-desoxy-ketitolwill vary from about 1 to about 15% by weight based on the hydrocarbonutilized in forming this new composition of matter.

As set forth hereinabove, the novel composition of matter of thisinvention is prepared by admixing a hydrocarbon or mixture ofhydrocarbons or a hydrocarbon fraction with a diaryl-desoxy-ketitol.This mixing can be carried out in any desired manner, as for example, inthe batch type operation. The mixing can be carried out at roomtemperature or higher as is desirable, Since the solubility of thediaryl-desoxy-ketitols in hydrocarbons is limited it is often desirable,and in some cases, necessary, to heat the mixture to form a clearsolution which on cooling sets to a clear stifi gel. This heating can becarried out up to temperatures of 200 C. or higher, the limitingtemperature of course being the boiling point of the particularhydrocarbon utilized in forming this novel composition of matter. Thegels formed will range in type from semisolids or stiff gels down tovarying plastic semi-liquid types.

J The process of this invention is illustrated further by the followingexamples which are incorporated herein for the purpose of illustrationand with no, intention of unduly limiting the generally broad scope ofthis invention.

EXAMPLE I This example illustrates the preparation of gels fromhydrocarbons and the condensation product of fructose with two molecularproportions of toluene. The reaction of fructose with toluene wascarried out in the presence of liquid hydrogen fluoride at temperaturesranging from to 30 C. utilizing contact times of from about 3 to about66 hours.

An outline of the procedure used in reacting d-fructose with toluene inthe presence of hydrogen fluoride is as follows:- d-fructose and:toluene were'sealed in a turbo-mixer one liter autoclave. After coolingto about 40 C., hydrogen fluoride was added to the turbomixer autoclaveunder pressure from a weighed autoclave and the contents of theautoclave were then stirred for the required time at ice temperature,and in one case, at 30 C. At the end of the reaction time, a stream ofnitrogen was passed through the reactor for one to three hours, thusremoving most of the hydrogen fluoride. The autoclave was opened and thecontents transferred to a silver dish which was later placed in ahood-draft for 18 to 24 hours, after which the hydrogen fluorideremainingin the productwas minor. The product then was washed thoroughlywith pentane to remove pentane-soluble components after which it wasseparated into a cold water-soluble fraction and cold water-insolublefraction. Each of these three fractions was then Worked up separately toobtain the pure compounds therefrom. The desired product is found in thepentane-insoluble waterof diaryl-desoxy-ketitols insoluble fraction as an-propyl alcohol-soluble portion .6 thereof. The reactionscarned out andrecovery of 'desired condensation product are summarized in thefollowing table:

Table I.-Racli0n of d-jructose with toluene in the presence of hydrogenfluoride h b Grams d-Fructme 50 Tnlnonn 170 HF 220 Run N0 .21 22 23 2425 26 27 Conditions of reaction: I j

Temp., 0 0 0 0 0 0 30 Contact time, hrs 3 5 16. 7 20 45 66 a 3 Recovery,grams: 7

Pentane-soluble 2 2 1 l 10 24 Water-soluble- 42 50 39 35 15 10 1.3Water-insoluble 7 15 48 84 139 84 Net totaL; 49 67 76 84 99 159' 109.3

Toluene reacted, gms o 17 26 34 49 91 59 Percent of water-insolublematerial, also acetone-soluble 56 83 97 "100 100 50 Acetone-soluble, gms28 32 34 15 10' 0.6

Yield of CrsHmOa, gms 14 20 19 2 0 Yield of 020112403, 'gms 5 11 16 2846 5 Exclusive of pentane-soluble. Y

In run 26, the charge was: d-fructose, 75 grams; toluene, 215 gms.;HF,336grams. I I In'the work with fructose at 0' C., it was observedthat the reactionwas slow Three hours of,contacting at 0 C. resulted ina small amount of total reaction product but as the contact time wasincreased, the amount of toluene reacting also increased. The data givenin the table show that the water-soluble portion increased rapidly withtime and then fell off, while there was a steady increase in thewater-insoluble fraction with time.

An examination of the water-insoluble portion of the reaction productsshowed that itcontained a compound which could be isolatedby extractionand crystallization with normal propyl alcohol, by which method it wasrecovered in quantities amounting to about 30% of the water-insolublefraction. I

This substance hereinafter referred to as ditolyl-desoxyfructose meltsat 210 C. and has, been assigned the following structural formula:

man

HOCH

BK JOH HO OH I Di-p-tolyl desoxy-fructose It should be noted that theabove compound contains a cycloh'exane ring structure with the two arylgroups attached to the same carbon atom. This structure has beenassigned to this compound on the basis of the following evidence:

(1) Elementary analysis:

Shows a molecule containing two tolyl (01) residues, one fructoseresidue (05), and three oxygen atoms.

(2) Oxidation of the di-p-tolyl-desoxy-fi'uctose yielded4,4'-dicarboxybenzophenone. Therefore, the structural unit illustratedbelow is present:

noooQi-Q-ooon This shows that; the three oxygen atoms demanded by thestructural formula above are hydroxyl oxygen atoms.

(4) The compound contains no olefinic double bond. The compound isstable to alkaline permanganate solution and does not decolorizechloroform colored with bromine.

These data are all in accordance with the above-cited structure andexclude other possible structures except wherc'the saturated carbon ringmay be other than a C ring, i.e., a C ring.

All evidence considered, the above constitution is assigned to thediarylated fructose obtained. This is a4,4-bis-(4-methylphenyl)-x,x',x", cycloalkane triol and on the basis ofpresent evidence is considered to be 4,4-bis-(4-methylphenyl)-l,2,3-cyclohexane triol.

This compound, namely, 4,4-bis-(4-methylphenyl)-1,2, 3-cyclohexane triolforms stifl gels with benzene and other hydrocarbons. Five percent byweight of this compound was added to reagent grade benzene. The benzenewas heated to its boiling point during which time the4,4-bis-(4-methylphenyl)-l,2,3-cyclohexane triol dissolved. On coolingthe benzene solution set to a stiff gel ideal for use in the productionof military incendiaries. In similar experiments, the same compound wasobserved to gel pentane, cyclohexane, and other hydrocarbons.

EXAMPLE II l-sorbose was reacted with toluene in the presence ofhydrogen fluoride in a manner similar to that described in Example I.The following reactants were charged to a 1.1 liter turbomixerautoclave: 50 grams of 1-sorbose, 172 grams of toluene, 243 grams ofhydrogen fluoride. The mixture was contacted for 45 hours at 0 C. and atatmospheric pressure. At the end of this 45 hours, most of the hydrogenfluoride was flushed from the system by passing a stream of nitrogenthrough the autoclave. The reaction product, when practically free ofhydrogen fluoride Weighed 126 grams. From this .126 grams was obtained82.5 grams of a toluene-free, hydrogen fluoridefree product. Thisproduct was separated into 7 grams of a pentane-soluble material, 14grams of a water-soluble material, and 61.5 grams of a water-insolubleproduct.

From this latter water-insoluble product 18.5 grams of a pure materialmelting at 215 C. was obtained. Chromic acid oxidation of a portion ofthis pure material yielded 4,4-dicarboxybenzophenone, identified by itsdimethyl ester melting at 222-224 C. Equal parts of the sorbose productmelting at 215 C., and the fructose product melting at 209-210 C.(Example I) give a mixed melting point of 204206 C. and therefore thecompounds are assumed not to be identical. They are, however,stereoisomers and differ only in the configuration of their respectivethree asymmetric carbon atoms. The ditolyl-sorbose reaction product isthus assigned the structure:

I H- C It should again be noted that the di-p-tolyl-desoxy-sorbosecondensation product is assumed to contain a cyclohexane ring structure.

Five percent by weight of this di-p-tolyl-desoxy-sorbose was dissolvedin Warm benzene which on cooling formed a clear, stable, stifi gel.

I claim as my invention:

1. A gelled mixture of a hydrocarbon liquid and from about 0.1 to about25% by Weight of a diaryl-desoxyketitol.

2. A gelled mixture of a hydrocarbon liquid and from about 0.1 to about25% by Weight of a di-p-tolyl-desoxyketitol.

3. A gelled mixture of a hydrocarbon liquid and from about 0.1 to about25 by Weight of 4,4-bis-(4-methylphenyl)-1,2,3-cyclohexanetriol.

4. A gelled mixture of an aromatic hydrocarbon liquid and from about 0.1to about 25 by weight of a diaryldesoxy-ketitol.

5. A gelled mixture of an aromatic hydrocarbon liquid and from about 0.1to about 25 by weight of a di-ptolyl-desoxy-ketitol.

6. A gelled mixture of an aromatic hydrocarbon liquid and from about 0.1to about 25% by weight of 4,4-bis- (4methylphenyl)-1,2,3-cyclohexanetriol.

7. A gelled mixture of benzene and from about 0.1 to about 25% by weightof a diaryl-desoxy-ketitol.

8. A gelled mixture of benzene and from about 0.1 to about 25% by Weightof a di-p-tolyl-desoxy-ketitol.

9. A gelled mixture of benzene and from about 0.1 to about 25% by weightof 4,4-bis-(4-methylphenyl)- 1 ,2,3 -cyclohexanetriol.

References Cited-in the file of this patent UNITED STATES PATENTS1,783,133 Ohle et al. Nov. 25, 1930 2,460,803 Bonner et al. Feb. 8, 19492,472,276 Bonner et al. June 7, 1949 OTHER REFERENCES Ohle et al.:Chemical Abstracts, vol. 26 (1932), p. 1257.

Karrer: Organic Chemistry, Elsevier Pub. Co., Inc., N.Y., 4th ed.(1950), p. 830.

Berger: Chemical Abstracts, vol. 46 (1952), p. 1651..

1. A GELLED MIXTURE OF A HYDROCARBON LIQUID AND FROM ABOUT 0.1 TO ABOUT25% BY WEIGHT OF A DIARYL-DESOXYKETITOL.